Re: [Qemu-devel] [PATCH] fix linuxboot.bin and multiboot.bin to not hijack int19

[Gleb Natapov <gleb@redhat.com>]

On Tue, Feb 01, 2011 at 05:02:55PM -0600, Anthony Liguori wrote:
> On 01/31/2011 03:02 AM, Gleb Natapov wrote:
> >Currently linuxboot.bin and multiboot.bin option roms override int19
> >vector to intercept boot process. No sane option rom should do that.
> >Provide bev entry instead that will be called by BIOS if option rom
> >is selected for booting.
> >
> >Signed-off-by: Gleb Natapov<gleb@redhat.com>
> >---
> >
> >Note that this patch should be applied after qemu will upgrade to Seabios
> >that supports boot order. Otherwise there will be change in behavior
> >since option rom will not be selected for booting by default.
> 
> I don't think there's a SeaBIOS release yet that includes the boot
> order support.
> 
I thought for AHCI support you are going to move to latest Seabios HEAD.
If this is not the case the patch should wait.

> Regards,
> 
> Anthony Liguori
> 
> >diff --git a/pc-bios/optionrom/linuxboot.S b/pc-bios/optionrom/linuxboot.S
> >index c109363..79b3ae8 100644
> >--- a/pc-bios/optionrom/linuxboot.S
> >+++ b/pc-bios/optionrom/linuxboot.S
> >@@ -22,6 +22,8 @@
> >
> >  #include "optionrom.h"
> >
> >+#define PRODUCT "Linux loader"
> >+
> >  BOOT_ROM_START
> >
> >  run_linuxboot:
> >diff --git a/pc-bios/optionrom/multiboot.S b/pc-bios/optionrom/multiboot.S
> >index 9131837..069c4e8 100644
> >--- a/pc-bios/optionrom/multiboot.S
> >+++ b/pc-bios/optionrom/multiboot.S
> >@@ -20,6 +20,8 @@
> >
> >  #include "optionrom.h"
> >
> >+#define PRODUCT "multiboot loader"
> >+
> >  #define MULTIBOOT_MAGIC		0x2badb002
> >
> >  #define GS_PROT_JUMP		0
> >diff --git a/pc-bios/optionrom/optionrom.h b/pc-bios/optionrom/optionrom.h
> >index fbdd48a..95dbdda 100644
> >--- a/pc-bios/optionrom/optionrom.h
> >+++ b/pc-bios/optionrom/optionrom.h
> >@@ -93,31 +93,41 @@
> >  	.global 	_start;				\
> >      _start:;						\
> >  	.short		0xaa55;				\
> >-	.byte		(_end - _start) / 512;
> >+	.byte		(_end - _start) / 512;		\
> >+	lret;						\
> >+	.org 		0x18;				\
> >+	.short		0;				\
> >+	.short		_pnph;				\
> >+    _pnph:						\
> >+	.ascii		"$PnP";				\
> >+	.byte		0x01;				\
> >+	.byte		( _pnph_len / 16 );		\
> >+	.short		0x0000;				\
> >+	.byte		0x00;				\
> >+	.byte		0x00;				\
> >+	.long		0x00000000;			\
> >+	.short		_manufacturer;			\
> >+	.short		_product;			\
> >+	.long		0x00000000;			\
> >+	.short		0x0000;				\
> >+	.short		0x0000;				\
> >+	.short		_bev;				\
> >+	.short		0x0000;				\
> >+	.short		0x0000;				\
> >+	.equ		_pnph_len, . - _pnph;
> >
> >  #define BOOT_ROM_START					\
> >  	OPTION_ROM_START				\
> >-	push		%eax;				\
> >-	push		%ds;				\
> >-							\
> >-	/* setup ds so we can access the IVT */		\
> >-	xor		%ax, %ax;			\
> >-	mov		%ax, %ds;			\
> >-							\
> >-	/* install our int 19 handler */		\
> >-	movw		$int19_handler, (0x19*4);	\
> >-	mov		%cs, (0x19*4+2);		\
> >-							\
> >-	pop		%ds;				\
> >-	pop		%eax;				\
> >-	lret;						\
> >-							\
> >-    int19_handler:;					\
> >+    _bev:;						\
> >  	/* DS = CS */					\
> >  	movw		%cs, %ax;			\
> >  	movw		%ax, %ds;
> >
> >  #define OPTION_ROM_END					\
> >+    _manufacturer:;					\
> >+        .asciz "QEMU";					\
> >+    _product:;						\
> >+        .asciz PRODUCT;					\
> >      .align 512, 0;					\
> >      _end:
> >
> >--
> >			Gleb.
> >

--
			Gleb.